Hey Joe( that's got a ring to it( should be a hit )
firstly you shouldn't be running it on 25/1 try 40/1. im sure you will find your plugs oiled up and when that happens your wasting your time if your running the plugs that came with the motor dump them and put in a set of NKGs make sure your prop is at 1 o'clock get her wet and give her a flick remember your only starting one side 26cc so compression is not bad im sure your problem lies with the 25/1 mix i run red line oil and have had well over 400 flights on mine i also run that mix in my DA170 ect starting that tightens my rear up slightly as shes a 32x12 prop the XYZ is a great wee motor in fact i have ordered another one to fit in to a carf 2.3 ive bought just for pattern flying
regards Frank